To ensure an electrical conductivity, silver electrodes are used as bus electrodes constituting display electrodes in a plasma display panel (hereinafter, called a PDP). Though low-melting glass containing lead oxide as its main ingredient is conventionally used as the material of a dielectric layer provided to coat the bus electrodes, the dielectric layers used in recent years include no lead component in view of environmental consciousness (for example, refer to Patent Document 1).
It is demanded that the capacitance of the dielectric layer be reduced to minimize reactive power so that power consumption in the PDP can be lessened, meaning that the relative dielectric constant of the dielectric layer should be reduced. According to a conventional technique employed to form the dielectric layer having a small relative dielectric constant, porous fine particles are deposited on a glass plate (for example, refer to Patent Document 2).